Cytomegalovirus infection and graft rejection in renal transplantation

Background. Cytomegalovirus (CMV) infection and CMV disease have been assoc iated with acute and chronic graft rejection. The introduction of the sensi tive CMV antigenemia pp65 assay for detection of CMV infection allowed us t o study the time course of CMV infection and acute rejection and the long-t erm outcome in renal transplant recipients with and without a CMV risk cons tellation. Methods. Prospective single center study including 48 renal transplant reci pients at risk for CMV infection (donor and/or recipient CMV seropositive) and a control group of 36 CMV seronegative recipients of CMV seronegative k idney donors. Evidence of CMV infection was monitored by the CMV antigenemi a pp65 assay every 1 to 2 weeks and compared with the occurrence of acute r ejection in the posttransplant period and graft function at 5 years. Results. CMV infection developed in 83% (40/48) of patients of the CMV risk group within 4 months posttransplant. A total of 18 of patients experience d an acute rejection episode (control group 16/36; P=0.65), In 12/18 CMV in fection followed rejection and in three patients antigenemia preceded the d iagnosis of rejection. In three patients CMV antigenemia remained negative. Five-year follow up: Patient survival (44/48 vs. 31/36; P=0.48), graft sur vival (38/48 vs. 27/36; P=0.79), number of patients with at least one acute rejection episode: CMV risk group: 42.1%, control group 51% (P=0.46), seru m creatinine: CMV risk group:130 +/- 66 mu mol/liter, control group: 126 +/ - 37 mu mol/ liter (P=0.56), proteinuria: CMV risk group: 0.02 +/-0.02 g/mm ol creatinine, control group: 0.02 +/-0.02 g/mmol creatinine (P=1.0). Conclusion. CMV infection within 4 months posttransplant, as defined by a p ositive antigenemia assay was not found to be a risk factor for acute graft rejection or chronic graft dysfunction at 5 years.